Swivel chair



FIG. 1 is a perspective view of a swivel chair showing my new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a further perspective view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a back view thereof;

FIG. 6 is a left side view thereof, the right side being a mirror image thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines in the drawings depict portions of the swivel chair that form no part of the claimed design. 

CLAIM The ornamental design for a swivel chair, as shown and described. 